Preliminary studies in our laboratory indicate that when nerve growth factor (NGF), a naturally occurring protein that enhances growth of sympathetic neurons, is injected into newborn puppies, the hearts of these puppies undergo morphological and dynamic changes which resemble those changes observed in many with hypertrophic obstructive myopathy (asymmetrical septal hypertrophy). This proposal is designed to investigate in detail the hemodynamic and angiocardiographic changes induced by the administration of NGF to newborn puppies. The hearts of animals treated with NGF will be analyzed for catecholamine content. Mitochondrial respiration and calcium transport will be studied. Histochemical, light and electron microscopic studies will be conducted. Species specific (canine) NGF will be prepared and levels of circulating NGF determined by radioimmunoassay. A beta adrenergic blocking agent will be administered to determine whether or not this agent will block the effects of NGF. These data will permit us to determine if NGF is involved as an etiologic agent in obstructive cardiomyopathy. If NGF administration indeed results in the development of hypertrophic cardiomyopathy, then this study will permit accurate characterization of the animal model. Finally, the development of techniques for production and detection of species specific nerve growth factor and the study of the beta adrenergic blocking agents will serve as preparation for future clinical studies should they prove indicated.